Virtually all states have regulations requiring that large trucks or trailers employ mud flaps or mudguards mounted aft of the rear wheels to protect following motorists and pedestrians from debris such as rain, mud and stones picked up by the tires. This debris would otherwise be thrown out from the tire and hinder and perhaps even injure the motorist or pedestrian.
The employed mudguards or mud flaps are commonly elongate, generally rectangular flaps formed of flexible material mounted by its upper end from the vehicle body rearwardly of and in close proximity to the vehicle wheel mounted tire. The material forming the mud flap or guard is generally either a relatively stiff plastic material or a synthetic rubber with a strengthening interior fabric or cords. In either material, the mud flap or guard must be relatively stiff so that it does not tend to blow upwardly in the slipstream or flap excessively. When the mudguards or flaps are in a position other than substantially vertical, the splashing effect created by the moving wheels is not effectively controlled. Further, any continuous flexing movement of the mudguard or flap weakens the material thereof to the extent that its useful life is substantially reduced by material fatigue.
Further, particularly during darkness, the rear end of a truck or trailer are often insufficiently illuminated and passing or trailing vehicles may not be able to precisely discern the outline of the truck or trailer, thereby leading to potentially disastrous effects. For example, the rear wheels of the truck or trailer may be insufficiently illuminated, particularly during a dark night whereby a passing motorist tends to drift too close and a collision occurs, often at a high rate of speed.